Transparency can be used to create a new layout or to customize the look of your tiles.
Customize Your Tiles
Use transparency to hide all tile backgrounds, and only display the tile icons.
Easily create transparent tile backgrounds by checking the Transparent check box from Content > Branding > Design.
Create New Layouts
You can create new screen layouts using transparent icons and tiles.
After you create transparent tile backgrounds, add a transparent image to a layout block, whose action is set to No Action. Make sure not to add a title. Then add this layout block to the tiles you want to disappear.